DataTypes

MVM Data Types

The Micro Virtual Machine (MVM) supports several fundamental data types. These types are used in instructions, system calls, and within the standard library functions. The MVM uses a 64-bit architecture, but some instructions and functions can operate on smaller data types as specified by the SETTYPE instruction. All values are stored in memory as 64-bit Longs unless otherwise specified. The data type stored in the registers is tracked by using the RegisterData class which you can change at any time using the SETTYPE instruction. If an instruction or system call that operates on a smaller data type is used, but the register is a larger type, then the value will be truncated to fit that type.

Fundamental Data Types

Integer Types

Type	Size (bits)	Range	Notes
Byte	8	-128 to 127	Signed 8-bit integer.
Short	16	-32,768 to 32,767	Signed 16-bit integer.
Int	32	-2,147,483,648 to 2,147,483,647	Signed 32-bit integer.
Long	64	-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807	Signed 64-bit integer. This is the default data type for registers.

Floating-Point Types

Type	Size (bits)	Notes
Float	32	Single-precision floating-point number (IEEE 754).
Double	64	Double-precision floating-point number (IEEE 754).

String Type

Strings are represented as null-terminated sequences of characters in memory. Each character occupies one word (64 bits).

Boolean Type

Boolean values are represented using 64-bit Longs. The integer value of 0 represents false, and 1 represents true.

Register Data Types

The SETTYPE instruction allows you to change the data type stored in a register at runtime. This allows for flexible use of memory by being able to change data types as needed.

Data Type	Description	Size (bits)	Example
Byte	8-bit signed integer	8	settype G1 Byte
Short	16-bit signed integer	16	settype G1 Short
Int	32-bit signed integer	32	settype G1 Int
Long	64-bit signed integer (default for registers).	64	settype G1 Long (default)
Float	32-bit single-precision floating-point number (IEEE 754).	32	settype X1 Float
Double	64-bit double-precision floating-point number (IEEE 754).	64	settype X1 Double

Memory Representation

All values are stored in memory as 64-bit Longs regardless of the data type. This is to ensure consistency throughout the memory. You can use smaller data types in registers, but memory always works with 64-bit Longs.

This document describes the data types used within the MVM. It's essential to understand these types when writing assembly code for the MVM.